A nanocrystal shows distinctive physical properties caused by the size, and applications as a new material are expected. In particular, it is reported that significantly large dielectric characteristics are shown in a BT/ST artificial superlattice thin film having a hetero interface between barium titanate (BaTiO3, BT), which is a ferroelectric substance, and strontium titanate (SrTiO3, ST) which is a paraelectric substance (NPL 1). If three-dimensionally bottoming-up of the hetero interface is allowed, further gigantic properties can be expected.